6.5TD Longevity/Effieciency/Performance

[hraney]

I was wondering what kinds of service life folks have been getting out of their 6.5's between overhauls. Also maybe an average mpg for different configurations. I have about 60k (according to the Previous owner) on a crate motor in my Crew cab 1 ton and have been getting about 12mpg average unloaded. Does that seem a little low to y'all? The truck is 4x4 and weighs 7100# emtpy so maybe I am being optimistic. It may be time for a set of injectors. I have already put a 3" downtube and 4" exhaust but no other mods. Also, how much "tweaking" will this motor stand? I don't plan on dragracing but I would be interested in what the upper range is on HP.

Thanks

[sschevelleman]

I usually see 300-400K miles between rebuilds if well maintained. Less if neglected. Injectors every 100K are an important part of longevity too. Neglected, they will cause premature engine failure from the leaking fuel washing lubricant off the pistons and cylinder walls.
Mileage...1500 series 18-20 mpg, 2500 series 17-18 mpg, 3500 series 15-16 mpg. Keep in mind rear end gearing has a lot to do with it also. If you have a 2500 with 4.10's, you won't see much better then 15-16mpg. The engines are actually quite strong if maintained. You can safely add an 80hp chip and even propane injection. Marine injectors work well too.

[totemtelemark]

Im driving a 93 1 ton, getting 16-17 mpg. Im considering air intake and 4" exhaust, what kind of mileage increases would I be looking at. Id like to get 20-22 mpg ideally

Thanks

[Scrufdog]

When I got my truck I was getting 17-18mpg @ 6000lbs, completely stock.

Now with everything I am still getting 17-18mpg @ 6500lbs.

[hraney]

Im driving a 93 1 ton, getting 16-17 mpg. Im considering air intake and 4" exhaust, what kind of mileage increases would I be looking at. Id like to get 20-22 mpg ideally

Thanks

I have talked to very few folks who get consistently in the 20's and actually use their trucks. I had a '95 3/4 Cheyenne reg cab LB 6.5TD and 5sp w/ 4.10 and the BEST I ever got was 21 (long trip coming down out of the mountains in NM, just me, the wife and luggage). Avg was 15/16. I added a 3" straight exhaust and the SS-107 intake and I averaged 15/16.
My latest aquisition, a 97 Crew cab 1 ton, auto w/ 4.10s has been averaging 12.5 unloaded, around town. And that is since adding a 3" downtube and 4" exhaust.
Both of these trucks I consider driven w/ a light touch.

[sschevelleman]

Don't forget diesel fuel radically changed October 15th. The new ULSD diesel fuel was introduced. It produces less hp, and gives 1-2 mpg less also. Additionally, it lubricates much less the std diesel fuel did due to almost no sulfur, and unless you add a good conditioner to every tankful, premature pump and injector wear will result. But, we're "saving the environment"!! (so they say)

[Matt Bachand]

What is the advantage of Marine injectors over regular injecters?

[Kilborg]

While im new to the 6.5 world i typically see them anywhere from 100-300k in many of the vehicles i wrench on. Most guys iv asked seem pretty happy with how the motors have worked out for them minus a few of the faults that most of you guys have addressed on your own rigs.

[big97daddy]

BIGDADDY HERE, I have a 94 Chevy with a 6.5td k1500 it just turned over 300,000 last month only thing thats ever been done was a SSheat sink and pump driver,that was done last month,it started stalling and would fire right back up. NO PUMP-NO INJECTORS GLOW PLUGS LAST YEAR LOTS OF OIL CHANGES AND FILTERS,shes ready to go to california today if you wanted:)

[RckyMtNDeZL]

I am the 2nd owner of my rig,my grandfather willed it to me when he passed away. I immediately dumped 5k in maintenance it needed badly....plugs,injectors, IP, pmd, whatever the dealer could do. That was at 70k, I have kept up with the routine stuff religiously and aside from the PMD I have been trouble free. The 6.5 is reliable, to some maybe not. But to the people who know how to actually maintain a vehicle...it can go a long long way.